Hi murphycivil-
The 502 bad gateway can occur when your computer's server tries to connect to the QuickBooks server and it fails. Often times if you refresh your screen by holding CTRL+R on Windows / CMMD + R on Mac, you should be able to reload QuickBooks.
If you're still receiving the 502 bad gateway, could you let us know what browser are you using to log in to QuickBooks?
-Christine
